For a diagnosis of ADHD, when must the symptoms appear?

For a diagnosis of Attention-Deficit/Hyperactivity Disorder (ADHD), symptoms must appear before age 12. This criterion is defined in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition), which is the official manual used by healthcare professionals to diagnose mental disorders. The presence of symptoms before age 12 is essential for establishing a diagnosis of ADHD, as it indicates that the condition was present during the critical periods of development in childhood.

Identifying the onset of symptoms within this timeframe is important because it helps ensure that the behaviors are developmental in nature and consistent with ADHD's characteristics, rather than a response to environmental factors later in life. Thus, focusing on the requirement for symptoms to appear before age 12 is key to accurately diagnosing ADHD and implementing the appropriate interventions to support the individual.